(a) Related Field
The present system and method relate to a liquid crystal display, and more particularly, to a vertically aligned (VA) liquid crystal display with improved transmittance.
(b) Description of the Related Art
A liquid crystal display generally includes two display panels on which electric field generating electrodes such as a pixel electrode and a common electrode are formed, and a liquid crystal layer interposed between the two display panels. The liquid crystal display displays an image by applying a voltage to the field generating electrodes to generate an electric field in the liquid crystal layer. Particularly, by controlling the strength of electric field being generated, the liquid crystal display is able to manipulate the alignment of the liquid crystal molecules in the liquid crystal layer, and thereby control the polarization of incident light transmitted by the liquid crystal layer.
A vertically aligned liquid crystal display generally refers to one in which the liquid crystal molecules are aligned with their long axes perpendicular to the planar surfaces of the display panels in the absence of an electric field. A vertically aligned liquid crystal display generally has a higher contrast ratio is large and is easily configurable to achieve a wide viewing angle.
To implement a wide viewing angle in a vertically aligned liquid crystal display, each pixel of the liquid crystal display may be formed to include a plurality of domains in which the liquid crystal molecules in each domain have an alignment direction different from that of the liquid crystal molecules in the other domains. A means of forming the plurality of domains may include forming cutouts such as minute slits on the field generating electrode. Specifically, the plurality of domains are formed when the liquid crystal molecules are aligned by a fringe field formed between the edges of the cutouts and the field generating electrodes facing the edges of the cutouts.
A display area of a pixel may be sectored into a plurality of domains by domain-forming members. The liquid molecules in each domain are generally inclined in the same direction. The domain-forming members may be formed on a substrate of both display panels (e.g., an upper substrate and a lower substrate), or only on one substrate (e.g., the lower substrate).
Recently, a method has been developed to improve the response speed of the liquid crystal display while providing a wide viewing angle. The method pre-tilts the liquid crystal molecules so that the liquid crystal molecules are tilted even in the absence of an electric field. In one case, an alignment layer having various aligning directions may be used to pre-tilt liquid crystal molecules in the various directions. In another case, an alignment aid that can be hardened after applying an electric field may be added to the liquid crystal layer to pre-tilt the liquid crystal molecules of the liquid crystal layer in predetermined directions. The alignment aid may be hardened by heat or light such as ultraviolet rays. The electric field may be generated in the liquid crystal layer by applying a voltage to the electric field generating electrodes.
However, if an alignment aid for pre-tilting the liquid crystal molecules is used in the manufacture of the liquid crystal display, additional processes (e.g., hardening process for hardening the alignment aid) and costs may be required, and the manufacturing process may become complicated.